Wireless computing devices, such as laptop computers, personal digital assistant devices, etc., that communicate with other devices through wireless signals are becoming increasingly popular. Wireless computing devices are typically battery-powered. Since the amount of power a battery can provide is rather limited, minimizing the power consumption of a device in order to extend its operation time is an important consideration in the design of battery operated wireless devices.
A particular component of a wireless device that consumes a significant amount of power is the network interface card (NIC), which handles the wireless transmission and reception of network communication data. It has been estimated that on average, about 20% of the total power available to a wireless device is dissipated as a result of the connection of a NIC, or other wireless LAN interface component. This phenomenon is due to the fact that the NIC and wireless device must be in a constant “listening” state in order to receive and transmit data via the network. As a result, battery power is used to power the device and the NIC even when no message is being sent or transmitted.
To overcome this challenge, various schemes for reducing the battery consumption in wireless devices have been developed and implemented within conventional wireless devices. One such power management scheme involves completely powering off the NIC of the device during periods in which no data communication is occurring for that device. While this mode of operation aids in reducing the power consumption of the device, it can hinder reconnection of the relevant device to the network when needed.
Another power management scheme often employed by wireless devices entails switching the NIC between different power states having different power consumption levels. Those states include high-power states, in which the NIC is powered up to enable the transmission of network communication data, and low-power states in which the network interface card is put in a sleep mode. Similar to the above-described scenario in which the NIC is powered off, when the NIC is in a low-power state, data transmissions can be significantly delayed while the NIC attempts to reconfigure with the network. Resultantly, the delayed data has to be temporarily stored in a queue until the NIC is switched back to the high-power state where it is ready for data communication. A significant amount of delayed network traffic data may be accumulated in the transmission queue if the interface network card is kept in the low-power state too often, or for too long.